In a lost wax investment casting process it is important to properly align a wax gate such that a ceramic shell can be adequately filled with molten metal. Proper alignment is also required to ensure proper grain growth as the molten metal cools.
Traditionally, assemblers have manually attached wax gates to a part based on a sample photograph, or by using gating fixtures made from aluminum or wax. In the first situation, assemblers would look at the photograph and then use rulers and protractors to measure gate lengths and degree of orientation with respect to a wax pattern of the part. Wax gates would then be cut out and wax welded to the wax pattern based on the measurements. This process generates a significant amount of human error, with each pattern being assembled differently from the next despite best efforts to provide consistent attachment points.
The use of wax or aluminum fixtures also has disadvantages. Various fixture pieces need to be measured, cut to a desired shape, and then attached to each other to form a finished fixture. These types of fixtures are difficult and time consuming to make. Further, cutting and machining these fixtures wastes material, thereby increasing cost.
Thus, there is a need to provide an improved gating structure for lost wax investment casting processes.